DE102008057051B4 - Materials for organic electroluminescent devices - Google Patents

Abstract

Compound of the general formula I or the general formula II whereM is Pt in the oxidation state +2, Ar, identically or differently on each occurrence, is an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which can be substituted by one or more radicals R, Y is the same or different on each occurrence is C or N, with the proviso that always two C atoms and two N atoms are bonded to the metal, X is an aromatic or heteroaromatic ring system with 5 to 15 aromatic ring atoms, selected from, which with one or more radicals R can be substituted; R, identically or differently on each occurrence, is a straight-chain alkyl group with 1 to 3 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which in each case can be substituted by one or more radicals R2 , R1 identically or differently on each occurrence, H, D, an alkyl group with 1 to 10 carbon atoms, or an aromatic isches or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which can be substituted by one or more radicals R2, R2 is H, F or an aliphatic, aromatic and / or heteroaromatic hydrocarbon radical with 1 to 10 carbon atoms, identically or differently on each occurrence , where two or more substituents R2 can also form a mono- or polycyclic aliphatic or aromatic ring system with one another, n is identical or different on each occurrence and is 0 or 1, with a maximum of one n = 1 and where n = 0, that on the A hydrogen or radical R or Ar is bonded in place of the X concerned.

Description

The present invention relates to transition metal complexes of the general formulas I or II, in particular as emitter molecules in organic electronic devices, a layer and an electronic device which contain the compounds according to the invention, and a method for producing the compounds according to the invention.

Chelate complexes and organometallic compounds are used as functional materials in a number of different applications which, in the broadest sense, can be assigned to the electronics industry. In the case of the organic electroluminescent devices based on organic components (general description of the structure cf. U.S. 4,539,507 A and U.S. 5,151,629 A ) or their individual components, the organic light-emitting diodes (OLEDs), have already been launched on the market. Despite the successes that have already been achieved, further improvements are desirable here.

In recent years, increasing organometallic complexes that show phosphorescence instead of fluorescence have been discussed ( MA Baldo, S. Lamansky, PE Burrows, ME Thompson, SR Forrest, Appl. Phys. Lett., 1999, 75, 4-6 ). For theoretical spin-statistical reasons, up to four times the energy and power efficiency is possible when using organometallic compounds as phosphorescence emitters. The essential conditions for practical use here are, in particular, a long operating life, high stability against thermal stress and a low operating and operating voltage in order to enable mobile applications.

• • Viele der bekannten Metallkomplexe besitzen eine geringe thermische Stabilität. Diese führt bei einer Vakuumdeposition zwangsläufig immer zur Freisetzung organischer Pyrolyseprodukte, die zum Teil schon in geringen Mengen die operative Lebensdauer der OLEDs erheblich verringern (z. B.: R. G. Charles, J. Inorg. Nucl. Chem., 1963, 25, 45 ).

• • Ebenso bedingt die starke Wechselwirkung der Komplexeinheiten im Feststoff, insbesondere bei planaren Komplexen von d⁸-Metallen wie Platin(II), die Aggregation der Komplexeinheiten in der Emitterschicht, sofern der Dotierungsgrad etwa 0.1 % überschreitet, was nach derzeitigem Stand der Technik der Fall ist. Diese Aggregation führt bei Anregung (optisch oder elektrisch) zur Bildung sogenannter Excimere bzw. Exciplexe. Diese Aggregate weisen häufig eine unstrukturierte breite Emissionsbande auf, was die Erzeugung von reinen Grundfarben (RGB) erheblich erschwert bzw. vollständig unmöglich macht. In der Regel sinkt auch die Effizienz für diesen Übergang.
• • Aus dem oben gesagten geht außerdem hervor, dass die Emissionsfarbe stark vom Dotierungsgrad abhängt, einem Parameter, der insbesondere in großen Produktionsanlagen nur mit erheblichem technischen Aufwand exakt kontrolliert werden kann.

In addition to the individual weak points specific to each material, the class of known metal complexes has general weak points, which are briefly shown below:

• • Many of the known metal complexes have a low thermal stability. In the case of vacuum deposition, this inevitably leads to the release of organic pyrolysis products, some of which, even in small quantities, considerably reduce the operational life of the OLEDs (e.g .: RG Charles, J. Inorg. Nucl. Chem., 1963, 25, 45 ).

• • Likewise, the strong interaction of the complex units in the solid, especially in the case of planar complexes of d ⁸ metals such as platinum (II), causes the complex units to aggregate in the emitter layer if the doping level exceeds about 0.1%, which is the case according to the current state of the art is. When excited (optical or electrical), this aggregation leads to the formation of so-called excimers or exciplexes. These aggregates often have an unstructured broad emission band, which makes the generation of pure primary colors (RGB) considerably more difficult or completely impossible. As a rule, the efficiency for this transition also decreases.
• • From the above it can also be seen that the emission color depends strongly on the degree of doping, a parameter that can only be precisely controlled with considerable technical effort, especially in large production plants.

Known in OLED technology are metal complexes of the transition metals of the 10th group (Ni, Pd, Pt), in which the central metal has two aromatic N and two C atoms ( WO 2004/108 857 A1 , WO 2005/042 550 A1 , WO 2005/042 444 A2 , US 2006/0 134 461 A1 ) or two imine-like N atoms in combination with two phenolic O atoms ( WO 2004/108 857 A1 ) or via two aromatic N and two basic N atoms ( WO 2004/108 857 A1 ) are bound to the metal. The known compounds exhibit, inter alia, electroluminescence in the blue, red and green regions of the electromagnetic spectrum. Out US 2005/0 227 112 A1 platinum complexes are known which have a macrocyclic ligand that coordinates to the platinum via two aromatic carbon atoms and two imine N atoms. Pregosin et al. (J. Organomet. Chem. 1984, 273, 401-413) describes a palladium complex which has two bidentate ligands which coordinate to the palladium via an aromatic carbon atom and an imine nitrogen atom.

Nevertheless, there is still a need for further compounds which do not have the disadvantages mentioned above and which preferably show electroluminescence in the blue, red and green regions of the electromagnetic spectrum and can in particular also be used in substance as a light-emitting layer.

The object of the invention was therefore to provide such compounds.

Surprisingly, it has been found that complexes with imine-like N atoms in combination with aromatic C atoms or olefinic C atoms in combination with aromatic N atoms as phosphorescence emitters in OLEDs have a long operating life and, by bridging these ligands, high stability against thermal stress and achieve a low operating and operating voltage.

bereit, wobei

M

Pt in der Oxidationsstufe +2 ist,

Ar

gleich oder verschieden bei jedem Auftreten ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 10 aromatischen Ringatomen ist, welches mit einem oder mehreren Resten R substituiert sein kann,

Y

gleich oder verschieden bei jedem Auftreten C oder N ist, mit der Maßgabe, dass immer zwei C-Atome und zwei N-Atome am Metall gebunden sind,

X

ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 15 aromatischen Ringatomen ist, ausgewählt aus

welches mit einem oder mehreren Resten R substituiert sein kann;

R

gleich oder verschieden bei jedem Auftreten eine geradkettige Alkylgruppe mit 1 bis 3 C-Atomen, oder ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 10 aromatischen Ringatomen ist, das jeweils durch einen oder mehrere Reste R² substituiert sein kann,

R1

gleich oder verschieden bei jedem Auftreten H, D, eine Alkylgruppe mit 1 bis 10 C-Atomen, oder ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 10 aromatischen Ringatomen ist, das jeweils durch einen oder mehrere Reste R² substituiert sein kann,

R2

gleich oder verschieden bei jedem Auftreten H, F oder ein aliphatischer, aromatischer und/oder heteroaromatischer Kohlenwasserstoffrest mit 1 bis 10 C-Atomen ist, wobei zwei oder mehrere Substituenten R² auch miteinander ein mono- oder polycyclisches aliphatisches oder aromatisches Ringsystem bilden können,

n

bei jedem Auftreten gleich oder verschieden 0 oder 1 ist, wobei maximal ein n = 1 ist und für n = 0 gilt, dass an der Stelle des betroffenen X ein Wasserstoff oder Rest R oder Ar gebunden ist.

The present invention provides a compound of the general formula I for this purpose

ready, being

M.

Pt is in the +2 oxidation state,

Ar

is identically or differently on each occurrence an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which can be substituted by one or more radicals R,

Y

is identical or different on each occurrence, with the proviso that two C atoms and two N atoms are always bonded to the metal,

X

is an aromatic or heteroaromatic ring system with 5 to 15 aromatic ring atoms selected from

which can be substituted by one or more radicals R;

R.

identically or differently on each occurrence is a straight-chain alkyl group with 1 to 3 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which can in each case be substituted ^{by one or more radicals R 2,}

R1

identically or differently on each occurrence is H, D, an alkyl group with 1 to 10 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which can in each case be substituted ^{by one or more radicals R 2,}

R2

identically or differently on each occurrence is H, F or an aliphatic, aromatic and / or heteroaromatic hydrocarbon radical with 1 to 10 carbon atoms, where two or more substituents R ^{2 can} also form a mono- or polycyclic aliphatic or aromatic ring system with one another,

n

is on each occurrence, identically or differently, 0 or 1, with a maximum of one n = 1 and for n = 0, a hydrogen or radical R or Ar is bonded at the point of the X concerned.

bereit, wobei M, Ar, Y, X, R, R¹, R² und n die oben genannten Bedeutungen aufweisen.The present invention also provides a compound of the general formula II

ready, where M, Ar, Y, X, R, R ¹ , R ² and n have the meanings given above.

If the radicals and indices defined above occur more than once within a compound, the radicals, independently of one another, can be identical or different on each occurrence, according to the respective definition.

• Eine Arylgruppe im Sinne dieser Erfindung enthält 5 bis 60 C-Atome; eine Heteroarylgruppe im Sinne dieser Erfindung enthält 2 bis 60 C-Atome und mindestens ein Heteroatom, mit der Maßgabe, dass die Summe aus C-Atomen und Heteroatomen mindestens 5 ergibt. Die Heteroatome sind bevorzugt ausgewählt aus N, O und/oder S. Dabei wird unter einer Arylgruppe bzw. Heteroarylgruppe entweder ein einfacher aromatischer Cyclus, also Benzol, bzw. ein einfacher heteroaromatischer Cyclus, beispielsweise Pyridin, Pyrimidin, Thiophen, etc., oder eine kondensierte Aryl- oder Heteroarylgruppe, beispielsweise Naphthalin, Anthracen, Phenanthren, Chinolin, Isochinolin, etc., verstanden.

The following general definitions also apply within this invention:

• For the purposes of this invention, an aryl group contains 5 to 60 carbon atoms; For the purposes of this invention, a heteroaryl group contains 2 to 60 carbon atoms and at least one heteroatom, with the proviso that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. Here, under an aryl group or heteroaryl group, either a simple aromatic cycle, that is benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine, thiophene, etc., or a condensed aryl or heteroaryl group, for example naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc., understood.

Particularly preferred for the purposes of this invention is the group Ar in the general formulas I or II benzene, naphthalene, pyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, furan, thiophene, pyrrole, benzofuran, benzothiophene and indole, with benzene being most preferred , Naphthalene, pyridine, quinoline and isoquinoline.

Among the condensed aromatic groups for the purposes of this invention, naphthalene, quinoline, benzothiophene, benzofuran and indole are preferred. Of these, naphthalene and quinoline are particularly preferred. For the purposes of this invention, an aromatic ring system contains 5 to 60 carbon atoms in the ring system. A heteroaromatic ring system for the purposes of this invention contains 2 to 60 carbon atoms and at least one heteroatom in the ring system, with the proviso that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S.

An aromatic or heteroaromatic ring system in the context of this invention is to be understood as meaning a system which does not necessarily contain only aryl or heteroaryl groups, but also in which several aryl or heteroaryl groups are replaced by a non-aromatic unit (preferably less than 10% of that of H different atoms), such as B. an sp ³ hybridized C, N or O atom, can be interrupted. For example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene, etc. are to be understood as aromatic ring systems in the context of this invention, and likewise systems in which two or more aryl groups are, for example, replaced by one linear or cyclic alkyl group or are interrupted by a silyl group.

In the context of the present invention, _{preference is given to a C 1} to C ₄₀ alkyl group or an alkyl group having 1 to 40 C atoms in which individual H atoms or CH ₂ groups can also be substituted by the groups mentioned above the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, Cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, Understood heptynyl or octynyl. A C ₁ - to C ₄₀ -alkoxy group is preferably understood to mean methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy or 2-methylbutoxy.

An aromatic or heteroaromatic ring system with 5 - 60 aromatic ring atoms, which can also be substituted by the above-mentioned radicals R and which can be linked via any positions on the aromatic or heteroaromatic, is understood to mean in particular groups which are derived from benzene, Naphthalene, anthracene, phenanthrene, benzanthracene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzpyrene, biphenyl, biphenylene, terphenyl, terphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, dihydropyrene, tetrahydropyrene or isocyanate pyrene , Spirotruxes, spiroisotruxes, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine-6, benzo-5,6 quinoline, phenanthridine-6, benzo-5,6 quinoline, , 7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, Phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridza, pyrimidine-1,5, benzopyridza, pyrimidine-1,5, benzopyridza, diapyrimantene, quinoxazole 2,7-diazapyren, 2,3-diazapyren, 1,6-diazapyren, 1,8-diazapyren, 4,5-diazapyren, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubine, Naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1, 2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, Indolizine and benzothiadiazole.

wobei M, X, Y, R und R¹ die oben genannten Bedeutungen haben und Z gleich oder verschieden bei jedem Auftreten für CR oder N steht, besonders bevorzugt für CR.Preferred embodiments of the compounds according to formula I and II are the following general formulas III and IV

where M, X, Y, R and R ^{1 have} the meanings given above and Z, identically or differently on each occurrence, represents CR or N, particularly preferably CR.

1 3

5 7

8 9

10 11

12 14

15 16

17 19

18 21

22

31

32 33

34 35

36 37

38 41

43 44

45 46

48 In addition to the preferred compounds mentioned above, the compounds shown in Table 1 below are also particularly preferred: Table 1: Complexes according to the invention with Pt as the central metal

1 3

5 7th

8th 9

10 11

12th 14th

15th 16

17th 19th

18th 21

22nd

31

32 33

34 35

36 37

38 41

43 44

45 46

48

The compounds according to the invention are square-planar complexes which contain a four-coordinate platinum in the +2 oxidation state. The compounds according to the invention have triplet emission and have a very good service life, high efficiency, high stability to thermal stress and a high Tg (glass transition temperature).

wobei M, X, Y, Ar, R, R¹, R² und n die oben definierte Bedeutung haben.The invention also relates to a process for the preparation of a compound of the general formula I or II

where M, X, Y, Ar, R, R ¹ , R ² and n have the meaning defined above.

The compounds according to the invention according to formula I or II can be prepared by synthesis steps generally known to the person skilled in the art.

As a starting point for ligand synthesis, for example, the N-phenylbenzaldimines ( Tetrahedron Lett. 2007, 48 (40), 7177-7180 ), N, N'-dibenzyl-idene-o-phenylenediamine ( J. Chem. Res. 2006, (1), 1-2 ), N, N'-bis (2-naphthalenylmethylene) -1,2-benzenediamine ( J. Indian Chem. Soc. 2002, 79 (6), 502-504 ) and N, N'-di (benzylidene) -1,8-diaminonaphthalene ( Toxicological and Environmental Chemistry 2006, 88 (4), 579-586 ) serve.

In a first stage, the corresponding ligands are synthesized, which are combined in a further step to form the desired ligand system. This is followed by a reaction with the corresponding metal (Pt), which is usually used as a solution of a suitable metal salt, for example K ₂ PtCl ₄ .

A general synthesis procedure for the preparation of the metal complexes according to formula I or II is shown in methods (A) and (B).

Method (A)

Method (B)

The invention also relates to the use of the compounds according to the invention in an organic electronic device, in particular as an emitting compound. According to the invention, organic electroluminescent devices (OLEDs) or polymeric electroluminescent devices (PLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors ( O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field quench devices (O-FQDs), light-emitting electrochemical cells (LECs) or organic laser diodes (O-lasers), but especially organic ones Electroluminescent devices (= organic light-emitting diodes, OLEDs, PLEDs) are used.

The invention also relates to the use of the compounds according to the invention as charge transport material and / or charge injection material, preferably in a corresponding layer. These can be hole transport layers, hole injection layers, electron transport layers or electron injection layers. It can also be used as a charge blocking material.

The invention also relates to organic electronic devices, such as. B. organic electroluminescent devices or polymeric electroluminescent devices (OLEDs, PLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic Thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field quench devices (O-FQDs), light-emitting electrochemical cells (LECs) or organic laser diodes (O lasers), but in particular organic electroluminescent devices (= organic light-emitting diodes, OLEDs, PLEDs), containing one or more compounds according to formula I or II, as defined above. The organic electronic device contains anode, cathode and at least one layer which contains at least one organic or organometallic compound. However, the device can also contain inorganic materials.

The compound of the formula I or II is preferably present in the electronic device within a layer.

The invention thus also relates to a layer containing a compound of the formula I or II, as defined above.

The organic electroluminescent device contains a cathode, anode and at least one emitting layer. In addition to these layers, it can also contain further layers, for example one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers and / or charge generation layers (Charge-Generation Layers, IDMC 2003, Taiwan; Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device Having Charge Generation Layer). Interlayers, which for example have an exciton-blocking function, can also be introduced between two emitting layers. It should be noted, however, that it is not necessary for each of these layers to be present. These layers can contain compounds of the general formula I or II, as defined above.

In a preferred embodiment of the invention, the compound according to formula I or II is used as an emitting compound in an emitting layer or as a charge transport compound in a charge transport layer. The organic electroluminescent device can contain an emitting layer, or it can contain a plurality of emitting layers, at least one emitting layer containing at least one compound according to formula I or II, as defined above. If several emission layers are present, these preferably have a total of several emission maxima between 380 nm and 750 nm, so that overall white emission results, ie different emitting compounds that can fluoresce or phosphoresce are used in the emitting layers. Three-layer systems are particularly preferred, the three layers showing blue, green and orange or red emission (for the basic structure, see e.g. WO 2005/011 013 A1 ). The device can further include multiple charge transport layers.

If the compound according to formula I or II is used as an emitting compound in an emitting layer, it is preferably used in combination with one or more matrix materials. The mixture of the compound according to formula I or II and the matrix material contains between 1 and 99% by weight, preferably between 2 and 90% by weight, particularly preferably between 3 and 40% by weight, in particular between 5 and 15% by weight .-% of the compound according to formula I or II based on the total mixture of emitter and matrix material. Accordingly, the mixture contains between 99 and 1% by weight, preferably between 98 and 10% by weight, particularly preferably between 97 and 60% by weight, in particular between 95 and 85% by weight of the matrix material based on the total mixture Emitter and matrix material.

Preferred matrix materials are CBP (N, N-biscarbazolylbiphenyl), carbazole derivatives (e.g. according to WO 2005/039 246 A1 , US 2005/0 069 729 A1 , JP 2004 - 288 381 A1 ), Azacarbazole (e.g. according to EP 1 617 710 A1 , EP 1 617 711 A1 , EP 1 731 584 A1 , JP 2005 - 347 160 A2 ), Ketones (e.g. according to WO 2004/093 207 A2 or DE 10 2008 033 943 A1 ), Phosphine oxides, sulfoxides and sulfones (e.g. according to WO 2005/003 253 A2 ), Oligophenylenes, aromatic amines (e.g. according to US 2005/0 069 729 A1 ), bipolar matrix materials (e.g. according to WO 2007/137 725 A1 ), Silanes (e.g. according to WO 2005/111 172 A2 ), Zinc complexes (e.g. according to DE 10 2007 053 771 A1 ) or aluminum complexes (e.g. BAIq).

An organic electroluminescent device is also preferred, one or more layers being coated using a sublimation process. The materials are vapor-deposited in vacuum sublimation systems at a pressure of less than 10 ^-5 mbar, preferably less than 10 ^-6 mbar, particularly preferably less than 10 ^{-7 mbar.}

An organic electroluminescent device is likewise preferred, characterized in that one or more layers are coated with the OVPD (Organic Vapor Phase Deposition) process or with the aid of a carrier gas sublimation. The materials are applied at a pressure between 10 ^-5 mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and structured in this way (e.g. MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301 ).

Also preferred is an organic electroluminescent device, characterized in that one or more layers of solution, such as, for. B. by spin coating, or with any printing process, such as. B. screen printing, flexographic printing or offset printing, but particularly preferably LITI (Light Induced Thermal Imaging, thermal transfer printing) or ink-jet printing (inkjet printing) can be produced. This requires soluble compounds, which can be obtained, for example, by suitable substitution.

These methods are generally known to the person skilled in the art and can be applied by him without problems to organic electroluminescent devices containing compounds according to formula I or II, as defined above.

• • Im Gegensatz zu vielen Metallkomplexen gemäß dem Stand der Technik, die der teilweisen oder vollständigen pyrolytischen Zersetzung bei Sublimation unterliegen, weisen die erfindungsgemäßen Verbindungen eine hohe thermische Stabilität auf.
• • Organische Elektrolumineszenzvorrichtungen enthaltend Verbindungen gemäß Formel I oder II als emittierende Materialien weisen eine exzellente Lebensdauer auf.
• • Es sind blau, rot und grün phosphoreszierende Komplexe zugänglich, welche eine tiefblaue, effiziente rote oder auch grüne Emissionsfarbe und bei Verwendung in organischen Elektrolumineszenzvorrichtungen eine hohe Lebensdauer aufweisen. Dies ist ein deutlicher Fortschritt gegenüber dem Stand der Technik, da bislang blau, rot und grün phosphoreszierende Vorrichtungen nur mit schlechten Farbkoordinaten und insbesondere einer sehr schlechten Lebensdauer zugänglich waren.
• • Die erfindungsgemäßen Verbindungen, eingesetzt in organischen Elektrolumineszenzvorrichtungen, führen zu hohen Effizienzen und zu steilen Strom-Spannungs-Kurven bei gleichzeitig niedriger Einsatzspannung.

The compounds according to the invention and the organic electroluminescent devices produced with them are distinguished by the following surprising advantages over the prior art:

• In contrast to many metal complexes according to the prior art, which are subject to partial or complete pyrolytic decomposition during sublimation, the compounds according to the invention have a high thermal stability.
• • Organic electroluminescent devices containing compounds according to formula I or II as emitting materials have an excellent service life.
• • Blue, red and green phosphorescent complexes are accessible, which have a deep blue, efficient red or green emission color and, when used in organic electroluminescent devices, have a long service life. This is a clear advance compared to the prior art, since so far blue, red and green phosphorescent devices have only been accessible with poor color coordinates and, in particular, a very poor service life.
• The compounds according to the invention, used in organic electroluminescent devices, lead to high efficiencies and steep current-voltage curves with a simultaneously low threshold voltage.

These advantages mentioned above are not accompanied by a deterioration in the other electronic properties.

The invention is illustrated in more detail by the following examples, without wishing to restrict it thereby. The person skilled in the art can synthesize further compounds according to the invention without inventive work and use them in organic electroluminescent devices.

• Die nachfolgenden Synthesen werden, sofern nicht anders angegeben, unter einer Schutzgasatmosphäre in getrockneten Lösungsmitteln durchgeführt.

Examples:

• Unless otherwise stated, the following syntheses are carried out under a protective gas atmosphere in dried solvents.

• Zu einer Lösung aus 1,7g K₂PtCl₄ (4,1 mmol) in 130 ml Essigsäure wird unter N₂ eine Lösung aus entsprechendem Imin-Ligand (4,1 mmol) in 130 ml Essigsäure zugegeben und 3 Tage bei 90 °C gerührt. Nach Filtration wird der Feststoff im Vakuum getrocknet und anschließend unter Schutzgas umkristallisiert.

Complex synthesis (method A):

• To a solution of 1.7 g of K ₂ PtCl ₄ (4.1 mmol) in 130 ml of acetic acid, a solution of the corresponding imine ligand (4.1 mmol) in 130 ml of acetic acid is added _{under N 2 and at 90 ° C. for 3 days} touched. After filtration, the solid is dried in vacuo and then recrystallized under protective gas.

• Zu einer Lösung aus 0,57 g Allylpalladium(II)chlorid-dimer (1 mmol) in 25 ml MeOH wird unter N₂ eine Lösung aus entsprechendem Imin-Ligand (2 mmol) in 20 ml Methanol zugegeben und 4 Tage bei 40 °C gerührt. Nach Filtration wird der isolierte Feststoff mit weiteren 2 mmol entsprechendem Imin-Liganden in 130 ml Essigsäure für 3 Tage bei 90 °C gerührt. Nach Filtration wird der Feststoff im Vakuum getrocknet und anschließend unter Schutzgas umkristallisiert.

Complex synthesis (method B):

• To a solution of 0.57 g of allyl palladium (II) chloride dimer (1 mmol) in 25 ml of MeOH, a solution of the corresponding imine ligand (2 mmol) in 20 ml of methanol is added _{under N 2 and at 40 ° C. for 4 days} touched. After filtration, the isolated solid is stirred with a further 2 mmol of the corresponding imine ligand in 130 ml of acetic acid for 3 days at 90.degree. After filtration, the solid is dried in vacuo and then recrystallized under protective gas.

Example 1: Pt complex (9)

A solution of 11 g (41.5 mmol) of N, N'-dibenzylidene-o-phenylenediamine in 1300 ml _{is added under N 2} to a solution of 17.2 g of K ₂ PtCl ₄ (41.5 mmol) in 1300 ml of acetic acid Added acetic acid and stirred at 90 ° C for 3 days. After 72 h, the precipitated solid is washed with cold methanol, dried in vacuo and then recrystallized _{in EtOH abs under protective gas.} This gives 16 g (33.3 mmol) of crystalline solid. The overall yield is 87%.

Example 2: Pt complex (11)

To a solution of 17.2 g of K ₂ PtCl ₄ (41.5 mmol) in 1300 ml of acetic acid, a solution of 15.9 g (41.5 mmol) of N, N′-bis (2-naphthalenylmethylene) _{is added under N 2.} -1,2-benzenediaminediene was added to 1300 ml of acetic acid and the mixture was stirred at 90 ° C. for 3 days. After 72 h, the precipitated solid is washed with cold methanol, dried in vacuo and then recrystallized _{in EtOH abs under protective gas.} This gives 19.4 g (33.4 mmol) of crystalline solid. The overall yield is 81%.

Example 3: Pt complex (20)

A solution of 12.8 g (41.5 mmol) of N, N'-di (benzylidene) -1 _{is added under N 2} to a solution of 17.2 g of K ₂ PtCl ₄ (41.5 mmol) in 1300 ml of acetic acid , 8-diaminonaphthalene was added to 1300 ml of acetic acid and the mixture was stirred at 90 ° C. for 3 days. After 72 h, the precipitated solid is washed with cold methanol, dried in vacuo and then recrystallized _{in EtOH abs under protective gas.} This gives 17 g (32.1 mmol) of crystalline solid. The overall yield is 78%.

Example 4: Pt complex (1)

A solution of 2.17 g (12 mmol) of N-phenylbenzaldimine in 120 ml of methanol is added to a solution of 4.4 g (4.25 mmol) of bis (methylallylplatinum (II) chloride) in 150 ml of MeOH under N ₂ and stirred at 40 ° C for 4 days. After filtration, the isolated solid is stirred with 2.17 g (12 mmol) of N-phenylbenzaldimine in 780 ml of acetic acid at 90 ° C. for 3 days. After filtration, the solid is dried in vacuo and then recrystallized under protective gas. This gives 5.4 g (9.4 mmol) of crystalline solid. The overall yield is 80%.

Example 5: Manufacture and characterization of organic electroluminescent devices

Electroluminescent devices according to the invention can, as for example in WO 2005/003 253 A2 are described. The results of various OLEDs are compared here. The basic structure, the materials used, the degree of doping and their layer thicknesses are identical for better comparability. The first device example describes a comparison standard according to the prior art, in which the emission layer consists of the host material spiro-ketone and the guest material (dopant) Ir (ppy) ₃ or a compound _{according to the invention.} Furthermore, OLEDs of various structures are described, in each case the host material is spiro-ketone. OLEDs with the following structure are produced in the same way as the above-mentioned general procedure: Hole Injection Layer (HIL) 20 nm 2,2 ', 7,7'-tetrakis (di-para-tolylamino) spiro-9,9'-bifluorene Hole transport layer (HTL) 20 nm NPB (N-naphthyl-N-phenyl-4,4'-diaminobiphenyl) Emission Layer (EML) 40 nm host: spiro-ketone (SK) (bis (9,9'spirobifluoren-2-yl) ketone) dopant: Ir (ppy) ₃ (10% doping, vapor-deposited; synthesized according to WO 03/0068526 ) or compound according to the invention. Electron Conductor (ETL) 20 nm AlQ ₃ (Tris (quinolinato) aluminum (III). cathode 1 nm LiF, then 150 nm Al.

For the sake of clarity, the structures of Ir (ppy) ₃ and spiro-ketone are shown below:

The compounds according to the invention used are shown below:

These not yet optimized OLEDs are characterized as standard; For this purpose, the electroluminescence spectra, the efficiency (measured in cd / A) as a function of the brightness, calculated from current-voltage-brightness characteristics (IUL characteristics), and the service life are determined. The results of the device measurement are summarized in Table 3. The devices containing the compounds according to the invention show an improved service life with comparable efficiency. Table 3: Device results with spiro-ketone as host material and with Ir (ppy) ₃ or compounds according to the invention as dopant E.g. EML Max. Efficiency [cd / A] Voltage [V] at 1000 cd / m ² CIE (x, y) Lifespan, initial brightness 1000 cd / m ² [h] 6th SK: 10% Ir (ppy) ₃ 30th 4.4 0.38 / 0.57 7700 7th SK: 10% Ex. 1 28 4.2 0.31 /0.60 12000 8th SK: 10% Ex. 2 35 4.1 0.34 / 0.60 1100

Claims (8)

Compound of the general formula I.

or the general formula II

where M is Pt in the oxidation state +2, Ar, identically or differently on each occurrence, is an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, which can be substituted by one or more radicals R, Y identically or differently on each occurrence is C or N is, with the proviso that there are always two C atoms and two N atoms bonded to the metal, X is an aromatic or heteroaromatic ring system with 5 to 15 aromatic ring atoms, selected from

which can be substituted by one or more radicals R; R, identically or differently on each occurrence, is a straight-chain alkyl group with 1 to 3 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, each of which can be substituted ^{by one or more radicals R 2 , R 1 is} identical or different on each occurrence is H, D, an alkyl group with 1 to 10 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 10 aromatic ring atoms, each of which can be substituted ^{by one or more radicals R 2 , R 2} identically or differently each occurrence is H, F or an aliphatic, aromatic and / or heteroaromatic hydrocarbon radical with 1 to 10 carbon atoms, where two or more substituents R ^{2 can} also form a mono- or polycyclic aliphatic or aromatic ring system with one another, n being the same on each occurrence or is different 0 or 1, where at most one n = 1 and where for n = 0 it is true that at the point of the X concerned Hydrogen or radical R or Ar is bonded. Connection after Claim 1 , characterized in that the group Ar is selected from benzene, naphthalene, pyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, furan, thiophene, pyrrole, benzofuran, benzothiophene and indole, most preferably benzene, naphthalene, pyridine, quinoline and isoquinoline. Connection after Claim 1 or 2 according to formulas III and IV

where M, X, Y, R and R ^{1 are} those in Claim 1 and Z, identically or differently on each occurrence, is CR or N, preferably CR. A method for producing a compound according to one or more of the Claims 1 to 3 , characterized in that the free ligand is reacted with a corresponding metal salt to form a complex. Use of compounds according to one or more of the Claims 1 to 3 in an organic electronic device, in particular in organic electroluminescent devices (OLEDs) or polymeric electroluminescent devices (PLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field quench devices (O-FQDs), light-emitting electrochemical cells (LECs) or organic laser diodes (O-lasers), in particular, however, organic electroluminescent devices (= organic light-emitting diodes, OLEDs, PLEDs) are used. Layer containing at least one compound according to one or more of the Claims 1 to 3 . Organic electronic devices, in particular organic electroluminescent devices or polymeric electroluminescent devices (OLEDs, PLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O -LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field quench devices (O-FQDs), light-emitting electrochemical cells (LECs) or organic laser diodes (O-lasers), containing one or more Connections according to one or more of the Claims 1 to 3 . Organic electroluminescent device according to Claim 7 , characterized in that the connection according to one or more of the Claims 1 to 3 is used as an emitting compound in an emitting layer or as a charge transport compound in a charge transport layer or charge injection layer.